public Canvas getViewPanel() {
DataSource dataSource = new DataSource();
dataSource.setID("valueTransform");
MaskValidator maskValidator = new MaskValidator();
maskValidator.setMask("^\\s*(1?)\\s*\\(?\\s*(\\d{3})\\s*\\)?\\s*-?\\s*(\\d{3})\\s*-?\\s*(\\d{4})\\s*$");
maskValidator.setTransformTo("$1($2) $3 - $4");
DataSourceTextField dsTextField = new DataSourceTextField("phone");
dsTextField.setTitle("Phone");
dsTextField.setValidators(maskValidator);